Lambda-shaped beams have greater torsional rigidity than beams of other configurations, such as I-beams, or H-beams, and have particular application as the supporting structure for a ramp of a dockboard. A typical dockboard is mounted in a pit or depression in a loading dock and includes a ramp that is pivoted at its rear edge to the supporting structure and is movable between a generally horizontal cross traffic position and an upwardly inclined position. Hinged to the forward edge of the ramp is a lip that can be moved from a downwardly hanging pendant position to an outwardly extending position where it forms an extension to the ramp. In operation, the extended lip is adapted to engage the bed of a truck located in front of the dock to provide a continuous platform for material handling equipment moving between the dock and the truck bed.
As the material handling equipment, such as fork lift trucks, do not apply a force equally to all areas of the ramp as the truck moves between the dock and the truck bed, the ramp is subjected in use to considerable torsional stress.
To withstand the torsional stress, the supporting beams, as shown in U.S. Pat. No. 4,068,338 have been formed with a lambda configuration. The lambda beams, which can have a length in the range of about 6 to 12 feet, are normally formed by a rolling process. As rolling mill tooling is extremely expensive, there has been a need to produce lambda-shaped beams by other less expensive procedures.